A COUPLE of days after Jeremy Corbyn announced he would stand for the Labour Party leadership, I was sat in a cafe with CND leader Kate Hudson.

“This is wonderful,” she told me, “something the entire left can unite around.”

A man dismissed as the token candidate of an old-fashioned socialist fringe a couple of months ago has now stormed to victory.

Denunciations from almost the entire Labour hierarchy, including two former prime ministers and countless ex-Cabinet members, only boosted his appeal.

And Corbyn has triumphed even despite an unprecedented and extremely controversial “purge” of registered supporters conducted by the panicked party bureaucracy.

In the course of the campaign he has not just united the left, as Hudson predicted, but inspired hundreds of thousands of people who had never been political before to sign up to support him.

How has he done it? After Labour’s defeat in May few of us could have predicted anything like this.

By 6am on the morning of May 8, as Labour’s loss became clear, Blairite has-beens were popping up on television screens to denounce Ed Miliband as having taken Labour too far to the left to be electable.

Early signals from Andy Burnham, Yvette Cooper and Liz Kendall — talked of in the British press back then as the “three main” candidates even after Corbyn entered the race — were that the party leadership agreed. All were pitching to the right.

The Morning Star held otherwise, pointing to the demolition of Labour in Scotland by the Scottish National Party — a group whose economic record is anything but socialist but which was able to mount a very effective campaign around slogans of anti-austerity, a rise in the Labour vote in England and the fact that more voters stayed at home than opted for any political party.

In fact, the 2015 vote, while providing a majority for the Conservatives — with the support of a mere 24 per cent of the electorate — indicated huge disaffection with the political system.

The vote for parties seen as “anti-Establishment,” whether the SNP, Ukip or the Greens, soared — a phenomenon illustrated most dramatically when 20-year-old Mhairi Black ousted long-term Labour heavyweight and former secretary of state for Scotland Douglas Alexander.

The signs were there that the British political system was continuing to lose popular consent, a trend shown in declining participation in elections and a constantly shrinking share of the vote given to the two main “establishment” parties, Tory and Labour, over recent decades.

So when a man with as solid an anti-Establishment record as Corbyn became a possible leader of one of those parties, there was a huge and receptive audience waiting.

Liberal newspapers have often given the impression that Corbyn has “come from nowhere,” and it is true that unlike the other three candidates he has not occupied senior positions in the Labour Party.

He was, however, already one of the most prominent and experienced socialist MPs in the country. A weekly Morning Star columnist for over a decade, he was of course well known to us at the paper — but he was also a champion of pretty much every progressive campaign in Britain.

Chair of the Stop the War Coalition, chair of the parliamentary Campaign for Nuclear Disarmament, a veteran of Britain’s anti-apartheid movement, of the Palestine Solidarity Campaign, a consistent opponent of Nato and war, an outspoken defender of trade unions, a fighter for the rights of the disabled — you couldn’t be a part of the British left without encountering Corbyn, whether on a picket line or a peace march or a rally against cuts.

This partly explains the huge reservoir of goodwill he was able to draw on when he decided to run for the leadership, possibly greater than would have been the case for anyone else.

But the campaign has also been given a tremendous boost by the support of much of the trade union movement, including Britain’s two largest unions Unite and Unison.

Britain’s trade unions are not led by fantasists. They would not have supported Corbyn if they did not believe he could win power for Labour.

Their support for the most left-wing leadership candidate in generations — possibly since party founder Keir Hardie himself — is part of a growing recognition that the supposed “compromises” made by Labour under Tony Blair, Gordon Brown and Ed Miliband in order to increase the party’s appeal had been a disaster.

They had been appalling for the country, because “compromise” meant in practice capitulation to a neoliberal political programme of increasing privatisation and inequality, launched in this country by Margaret Thatcher but continued by every government since.

They had been appalling for the world, since Labour governments helped the United States to wage devastating and unprovoked wars in the Balkans, Middle East and central Asia, causing untold loss of life and immense suffering and dislocation, part of the consequences of which we see in today’s refugee crisis.

And they didn’t even work. Labour lost five million votes under Tony Blair and these have not come back. Nor have they been transferred to the Conservatives — most of these people have simply stopped voting.

Its share of the vote fell at every election after 1997 until 2015, when under a marginally more left-wing programme it finally rose — but not by enough to offset the collapse in Scotland and the Conservative gains from the implosion of the Liberal Democrats.

The labour movement has effectively declared that enough is enough — a radical challenge to a political consensus which is failing all of us is not only desirable, but actually necessary if the Labour Party is to avoid irrevocable decline.

While the issue of whether to support the Labour Party has always been controversial on the revolutionary left, the Morning Star has consistently argued that as the mass party of labour — the party formed by the trade unions and retaining vital links to them — it has a significant role to play.

Trade unionists, non-Labour socialists and Greens have long rubbed shoulders with left Labour supporters on any number of campaigns, and this victory should be seen as a boost for the whole of the left and a chance to build a movement of transformation and change.

Labour’s seemingly relentless march to the right caused many to conclude that the party was lost to ordinary working people forever, but no credible replacement with the necessary labour movement backing or public profile has ever emerged.

So Corbyn’s victory is absolutely to be welcomed. It shows the strength the left still has in the Labour Party — if not its representatives in Parliament — and marks the most serious challenge to Thatcherism since the miners’ strike 30 years ago.

He has given new life to socialist ideas which are now discussed and promoted as a serious ideology in Britain again.

We cannot underestimate the challenges we still face.

A restive parliamentary party still dominated by the right, a relentlessly hostile media owned by a handful of billionaires and of course the simple fact that we are still living under a hard-right Conservative government which is pushing through new rules to make strikes all but impossible — and break the links between trade unions and the Labour Party, with the aim of crippling the party’s finances.

But on the other hand we should not underestimate the opportunities this opens up. Whatever the jeers of the Establishment, Corbyn is no throwback to “old Labour.”

His calls for democratic public ownership, the democratisation of the Labour Party’s structures and those of the country and above all his anti-imperialist foreign policy stance mark him out not just from Blair but from Clement Attlee too.

Corbyn is more than a breath of fresh air. He has the potential to radically change Britain for the better.

Now let’s make him Prime Minister.

• Ben Chacko is editor of the Morning Star.